Throughput of communication devices or information devices is being improved dramatically. In recent years, frequencies of signals transmitted in or between such devices are being increased, and there is a possibility that deterioration of a signal bandwidth in a printed wiring board may be caused. In particular, deterioration of a signal bandwidth in a through hole in a printed wiring board with a multilayer wiring structure is problematic in improving the throughput. Thus, as a means of reducing deterioration of a signal bandwidth in a printed wiring board, the following techniques have been suggested.
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